A 3D printed breathalyzer that costs as little as $29 to make has been used to “sniff out” 17 different diseases, including Parkinson’s and eight types of cancer. The device uses gold nanoparticles that react to certain exhaled chemicals, and is claimed to be 86% accurate.

Scientists used a 3D printed breathalyzer to diagnoze 1,400 patients from across the world

It certainly seems unscientific when compared to other medical procedures, but smelling a patient’s breath has been an effective form of diagnosis since Ancient Greek times, when famed physician Hippocrates practiced the procedure to determine his patients’ illnesses. Back then, doctors would even go so far as to sniff a patients urine or taste their sweat.

The medical world is very different today, but scientists have just discovered a new way of detecting a number of dangerous diseases, using that very old principle of smelling a patient’s breath. Only this time it’s not the doctors that are doing the sniffing, but a $29 3D printed breathalyzer filled with gold nanoparticles.

Last week, researchers published their study, “Diagnosis and Classification of 17 Diseases from 1404 Subjects via Pattern Analysis of Exhaled Molecules,” in the journal American Chemical Society Nano. The study details how a 3D printed device containing a sensor array of carbon nanotubes is used to capture the unique “breathprint” of certain diseases.

The amazing new device has already been tested on more than 1,400 patients, and has proven to be as effective as a dog’s nose when it comes to sniffing out certain chemicals. Those chemicals in a patient’s breath, which are known as volatile organic compounds (VOCs), cause the gold nanoparticles in the breathalyzer to change their resistance, giving doctors a clear indication of whether a patient is ill.

The breathalyzer is as effective at detecting diseases as a dog's nose

“The inspiration for this device was a dog’s nose because dogs can be trained to recognize the scent of a disease in someone’s breath and distinguish it from a healthy person,” said Professor Hossam Haick, lead author on the study. “Instead of the nose, we have chemical sensors, and instead of the dog’s brain we have a computer algorithm, so we can communicate more about a disease than a dog sniffing it out. The detection rate of close to 90 per cent is the same.”

So while dogs are extremely effective at sniffing out diseases in patients, this 3D printed device can actually discriminate between a number of different diseases, giving doctors a clear readout of what it has picked up from a patient’s breath. At present, the device can detect 17 individual diseases, including chronic kidney failure, two forms of Parkinson’s disease, multiple sclerosis, Crohn’s disease, ulcerative colitis, irritable bowel syndrome, high blood pressure, and pre-eclampsia in pregnant women.

The diseases detectable by the breathalyzer and how they are chemically connected

In addition to those diseases, the 3D printed breathalyzer can also detect cancers. By asking patients to exhale into the device, doctors were able to detect signs of head and neck, lung, bowel, bladder, kidney, prostate, gastric, and ovarian cancer.

When detecting the 17 diseases, the 3D printed device recorded an 86 percent accuracy across a spread of 1,404 patients. The researchers believe that this large number of test subjects, which included patients of both sexes, of various ages, and from number of countries including the US and Israel, has helped to guarantee the validity of the study.

The researchers who have developed the 3D printed breath reader believe that the device could prove incredibly useful for doctors, and not only because of how accurate it is: “Patients who might be frightened to have a procedure like a colonoscopy will not be afraid of a breath test, and it could be used to screen healthy people,” Haick commented.

Chart of which VOCs are present in unique disease "breathprints"

Haick and the large research team behind the study hope that the 3D printed device could become widely used by doctors for screening patients. However, the breathalyzer could also have applications beyond medicine. According to Haick, several companies have already licensed the device for other applications, which may include the detection of food spoilage, airport security, or detecting the chemical signatures of explosive devices.